Electronic devices with touch screen input devices generally provide either a virtual keyboard or handwriting recognition as a text input method. A virtual keyboard presents a layout of virtual keys similar to physical keyboards on the touch screen. The user can tap individual virtual keys to input characters and access functions. Handwriting recognition requires that the user draws characters on the touch screen, often with a stylus. The system then tries to recognise the user input and convert it into a character. The recognition systems typically work by comparing the user drawn input to a library of character patterns and mathematically calculating the best pattern recognition value for that input.
With these text input methods additional functions can be provided by defining specific a drawing pattern for each function
Traditionally the backspace (delete) function is provided to the user by presenting a backspace key in the user interface.
With handwriting recognition, this backspace key has to be in a separate area than the handwriting recognition area. Therefore pressing this backspace key breaks the user's focus from inputting characters. Moving the stylus to the key takes time, and the general mental switch from drawing patterns to tapping buttons takes also some mental effort.
This is why some handwriting recognition systems also allow backspace entering with a gesture. Generally the gesture is a simple pen stroke from right to left. After lifting up the pen the system then recognizes the drawn stroke as a gesture and deletes the last recognized character.
With a virtual keyboard, the backspace key is generally presented in a manner similar to physical keyboards, i.e. as a separate key in the keyboard. The same problem is present in this button as with handwriting recognition, although to a lesser extent, since it is also tapped like the character buttons.
When inputting text the preservation of user focus is critical in establishing high input speeds and user satisfaction. The key task is the correct input of characters, either via a virtual keyboard or by handwriting recognition. Accessing additional relevant functions should be made simple and intuitive.
A problem relating to the backspace function is that in many cases the user is required to input more than one backspace. While tapping the backspace button multiple times is relatively simple, drawing the backspace gesture multiple times (lowering the pen, drawing the gesture, lifting the pen up, moving the pen back, drawing the gesture again etc.) is complicated.
It would therefore be desirable to improve the control of an electronic device using a gesture as a control input.